220688 has 20 divisors (see below), whose sum is σ = 460908. Its totient is φ = 101760.

The previous prime is 220687. The next prime is 220699. The reversal of 220688 is 886022.

It can be written as a sum of positive squares in 2 ways, for example, as 85264 + 135424 = 292^2 + 368^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is an Ulam number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 220688.

It is not an unprimeable number, because it can be changed into a prime (220681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 323 + ... + 738.

2²²⁰⁶⁸⁸ is an apocalyptic number.

It is an amenable number.

220688 is an abundant number, since it is smaller than the sum of its proper divisors (240220).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

220688 is a wasteful number, since it uses less digits than its factorization.

220688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1082 (or 1076 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 220688 is about 469.7744139478. The cubic root of 220688 is about 60.4309710614.

The spelling of 220688 in words is "two hundred twenty thousand, six hundred eighty-eight".